cpusets: decrustify cpuset mask update code

Decrustify the kernel/cpuset.c 'cpus' and 'mems' updating code. Other than subtle improvements in the consistency of identifying white space at the beginning and end of passed in masks, this doesn't make any visible difference in behaviour. But it's one or two hundred kernel text bytes smaller, and easier to understand. [akpm@linux-foundation.org: coding-style fix] Signed-off-by: Paul Jackson <pj@sgi.com> Reviewed-by: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cpusets: decrustify cpuset mask update code
Decrustify the kernel/cpuset.c 'cpus' and 'mems' updating code. Other than subtle improvements in the consistency of identifying white space at the beginning and end of passed in masks, this doesn't make any visible difference in behaviour. But it's one or two hundred kernel text bytes smaller, and easier to understand. [akpm@linux-foundation.org: coding-style fix] Signed-off-by: Paul Jackson <pj@sgi.com> Reviewed-by: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Paul Jackson · Linus Torvalds
1 parent 029190c515
Showing 1 changed file with 20 additions and 30 deletions Side-by-side Diff
kernel/cpuset.c
@@ -488,6 +488,14 @@
 			return -EINVAL;
 	}
  
+	/* Cpusets with tasks can't have empty cpus_allowed or mems_allowed */
+	if (cgroup_task_count(cur->css.cgroup)) {
+		if (cpus_empty(trial->cpus_allowed) ||
+		    nodes_empty(trial->mems_allowed)) {
+			return -ENOSPC;
+		}
+	}
+
 	return 0;
 }
  
  
@@ -710,11 +718,13 @@
 	trialcs = *cs;
  
 	/*
-	 * We allow a cpuset's cpus_allowed to be empty; if it has attached
-	 * tasks, we'll catch it later when we validate the change and return
-	 * -ENOSPC.
+	 * An empty cpus_allowed is ok iff there are no tasks in the cpuset.
+	 * Since cpulist_parse() fails on an empty mask, we special case
+	 * that parsing.  The validate_change() call ensures that cpusets
+	 * with tasks have cpus.
 	 */
-	if (!buf[0] || (buf[0] == '\n' && !buf[1])) {
+	buf = strstrip(buf);
+	if (!*buf) {
 		cpus_clear(trialcs.cpus_allowed);
 	} else {
 		retval = cpulist_parse(buf, trialcs.cpus_allowed);
@@ -722,10 +732,6 @@
 			return retval;
 	}
 	cpus_and(trialcs.cpus_allowed, trialcs.cpus_allowed, cpu_online_map);
-	/* cpus_allowed cannot be empty for a cpuset with attached tasks. */
-	if (cgroup_task_count(cs->css.cgroup) &&
-	    cpus_empty(trialcs.cpus_allowed))
-		return -ENOSPC;
 	retval = validate_change(cs, &trialcs);
 	if (retval < 0)
 		return retval;
  
  
  
  
@@ -830,40 +836,24 @@
 	trialcs = *cs;
  
 	/*
-	 * We allow a cpuset's mems_allowed to be empty; if it has attached
-	 * tasks, we'll catch it later when we validate the change and return
-	 * -ENOSPC.
+	 * An empty mems_allowed is ok iff there are no tasks in the cpuset.
+	 * Since nodelist_parse() fails on an empty mask, we special case
+	 * that parsing.  The validate_change() call ensures that cpusets
+	 * with tasks have memory.
 	 */
-	if (!buf[0] || (buf[0] == '\n' && !buf[1])) {
+	buf = strstrip(buf);
+	if (!*buf) {
 		nodes_clear(trialcs.mems_allowed);
 	} else {
 		retval = nodelist_parse(buf, trialcs.mems_allowed);
 		if (retval < 0)
 			goto done;
-		if (!nodes_intersects(trialcs.mems_allowed,
-						node_states[N_HIGH_MEMORY])) {
-			/*
-			 * error if only memoryless nodes specified.
-			 */
-			retval = -ENOSPC;
-			goto done;
-		}
 	}
-	/*
-	 * Exclude memoryless nodes.  We know that trialcs.mems_allowed
-	 * contains at least one node with memory.
-	 */
 	nodes_and(trialcs.mems_allowed, trialcs.mems_allowed,
 						node_states[N_HIGH_MEMORY]);
 	oldmem = cs->mems_allowed;
 	if (nodes_equal(oldmem, trialcs.mems_allowed)) {
 		retval = 0;		/* Too easy - nothing to do */
-		goto done;
-	}
-	/* mems_allowed cannot be empty for a cpuset with attached tasks. */
-	if (cgroup_task_count(cs->css.cgroup) &&
-	    nodes_empty(trialcs.mems_allowed)) {
-		retval = -ENOSPC;
 		goto done;
 	}
 	retval = validate_change(cs, &trialcs);
...	...	@@ -488,6 +488,14 @@
488	488	return -EINVAL;
489	489	}
490	490
	491	+ /* Cpusets with tasks can't have empty cpus_allowed or mems_allowed */
	492	+ if (cgroup_task_count(cur->css.cgroup)) {
	493	+ if (cpus_empty(trial->cpus_allowed) \|\|
	494	+ nodes_empty(trial->mems_allowed)) {
	495	+ return -ENOSPC;
	496	+ }
	497	+ }
	498	+
491	499	return 0;
492	500	}
493	501
494	502
...	...	@@ -710,11 +718,13 @@
710	718	trialcs = *cs;
711	719
712	720	/*
713		- * We allow a cpuset's cpus_allowed to be empty; if it has attached
714		- * tasks, we'll catch it later when we validate the change and return
715		- * -ENOSPC.
	721	+ * An empty cpus_allowed is ok iff there are no tasks in the cpuset.
	722	+ * Since cpulist_parse() fails on an empty mask, we special case
	723	+ * that parsing. The validate_change() call ensures that cpusets
	724	+ * with tasks have cpus.
716	725	*/
717		- if (!buf[0] \|\| (buf[0] == '\n' && !buf[1])) {
	726	+ buf = strstrip(buf);
	727	+ if (!*buf) {
718	728	cpus_clear(trialcs.cpus_allowed);
719	729	} else {
720	730	retval = cpulist_parse(buf, trialcs.cpus_allowed);
...	...	@@ -722,10 +732,6 @@
722	732	return retval;
723	733	}
724	734	cpus_and(trialcs.cpus_allowed, trialcs.cpus_allowed, cpu_online_map);
725		- /* cpus_allowed cannot be empty for a cpuset with attached tasks. */
726		- if (cgroup_task_count(cs->css.cgroup) &&
727		- cpus_empty(trialcs.cpus_allowed))
728		- return -ENOSPC;
729	735	retval = validate_change(cs, &trialcs);
730	736	if (retval < 0)
731	737	return retval;
732	738
733	739
734	740
735	741
...	...	@@ -830,40 +836,24 @@
830	836	trialcs = *cs;
831	837
832	838	/*
833		- * We allow a cpuset's mems_allowed to be empty; if it has attached
834		- * tasks, we'll catch it later when we validate the change and return
835		- * -ENOSPC.
	839	+ * An empty mems_allowed is ok iff there are no tasks in the cpuset.
	840	+ * Since nodelist_parse() fails on an empty mask, we special case
	841	+ * that parsing. The validate_change() call ensures that cpusets
	842	+ * with tasks have memory.
836	843	*/
837		- if (!buf[0] \|\| (buf[0] == '\n' && !buf[1])) {
	844	+ buf = strstrip(buf);
	845	+ if (!*buf) {
838	846	nodes_clear(trialcs.mems_allowed);
839	847	} else {
840	848	retval = nodelist_parse(buf, trialcs.mems_allowed);
841	849	if (retval < 0)
842	850	goto done;
843		- if (!nodes_intersects(trialcs.mems_allowed,
844		- node_states[N_HIGH_MEMORY])) {
845		- /*
846		- * error if only memoryless nodes specified.
847		- */
848		- retval = -ENOSPC;
849		- goto done;
850		- }
851	851	}
852		- /*
853		- * Exclude memoryless nodes. We know that trialcs.mems_allowed
854		- * contains at least one node with memory.
855		- */
856	852	nodes_and(trialcs.mems_allowed, trialcs.mems_allowed,
857	853	node_states[N_HIGH_MEMORY]);
858	854	oldmem = cs->mems_allowed;
859	855	if (nodes_equal(oldmem, trialcs.mems_allowed)) {
860	856	retval = 0; /* Too easy - nothing to do */
861		- goto done;
862		- }
863		- /* mems_allowed cannot be empty for a cpuset with attached tasks. */
864		- if (cgroup_task_count(cs->css.cgroup) &&
865		- nodes_empty(trialcs.mems_allowed)) {
866		- retval = -ENOSPC;
867	857	goto done;
868	858	}
869	859	retval = validate_change(cs, &trialcs);